Major experimental efforts are undertaken at the Relativistic Heavy Ion Collider (RHIC) [1]}, [2]}, [3]}, [4]} and the Large Hadron Collider (LHC) [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]} to study the conditions for the creation and the properties of the quark-gluon plasma (QGP), a deconfined partonic state predicted by the theory of strong interaction, Quantum ChromoDynamics (QCD) [14]}, [15]}.
Direct photons, which are defined as all photons that are produced directly in scattering processes and therefore do not originate from hadronic decays, are a powerful tool for exploring the QGP.
They are produced during all stages of the collision and are basically unaffected by final state interactions as they only participate in electromagnetic interactions [16]}.
Hence, they are sensitive to the early stages of the collision's evolution.
Since a variety of QGP signatures are also present in high multiplicity p–Pb or pp collision at the LHC [17]}, it is interesting to study if a direct photon signal at low \(p_{\mathrm {T}}\)  can be observed already in minimum bias pp collisions, as predicted for \(\sqrt{s}=7\)  TeV [18]}.
Experimentally, however, the main challenge for direct photon measurements is to distinguish them from the large background of decay photons.
